At the beginning, this master thesis briefly describes the principle of semiconductors. It states their types, methods of operation, fields of use, and it interprets the manner of semiconductor devices’ passivation. Then it introduces silicones, their properties and usage. Later on, this thesis summerize air humidity theory and materiál moisturing including mathematical interpretation. Next chapter is devoted to basics of dielectric materials’ behavior. And finally, the last part of this thesis estimates charakteristics of passivation materiál, Dow Corning HIPEC Q1-9205 silicone rubber.

Object of the master´s thesis is design of a high voltage power supply for testing insulation materials with output voltage 50 V - 2 kV at fixed frequency 50 Hz. The power supply is controlled by personal computer and measured data are sent back to the personal computer. The Universal Serial Bus (USB) is used for communication between the PC and the device.